Method of disinfection of refrigerator rooms



nitecl States Patent 3,484,187 METHOD OF DISINFECTION OF REFRIGERATOR ROOMS Irena Malinowslra, Ul. Rakowiecka 41b/ 10; Celina Myslinska, Ul. Basniowa 3/77; and Ewa Urbanska, Ul. Dabrowskiego 73 m 18, all of Warsaw, Poland No Drawing. Filed Dec. 14, 1966, Ser. No. 601,562 Claims priority, application Poland, Dec. 18, 1965, P 112,094 Int. Cl. A611 13/00, 3/00; A0111 9/20 US. Cl. 2158 Claims ABSTRACT OF THE DISCLOSURE A mist of a disinfectant substance is sprayed into a refrigerated room which is at a temperature between 0 C. and 20 C. in order to disinfect such room, said disinfectant substance having a freezing point below 20 C. and consisting essentially of an active disinfectant dissolved in a solution containing an alcohol antifreeze substance and water.

This invention relates to a method of disinfection of refrigerated rooms at an air temperature up to 20 C.

A refrigerated room is an isolated room in which the following climatological conditions are kept: an air temperature of l8 C. to 38 C., a relative humidity of 75-95%, the exchange of the air as well as its circulation being assured by means of some refrigeration equipment.

The walls, ceilings and floors of refrigerated rooms are insulated to diminish the penetration into them of warmth from their environment. The isolation should form a continuous and closed coating around the whole refrigerated block. This however, for some technical reasons, is impossible to achieve in practice. The difference between the temperature on one side of the partition surrounding the refrigerated chamber and the pressure of water particles contained in the air facilitate the penetration of air into chambers of lower temperature. It is, therefore, impossible to avoid, in practice, the penetration of humidity into the cold storage rooms, whereby the penetration of humidity increases with the difference of temperature between the inside part of the chamber and its environment or between the temperature in adjoining rooms.

Nevertheless to lower the cost of isolation which is very high and plays a considerable part in the total cost of the cold storage plant, insulation is sometimes not made between adjacent refrigerated rooms. It is then assumed that the climatic conditions of adjacent rooms would always be kept at the same level.

In the refrigerator rooms, the perishable food is kept in cooled or in frozen state, and the said rooms must fulfill not only the requirements of the techniques of freezing technology but also some hygienic and sanitary rules should be observed. According to the sanitary rules the refrigerated rooms should be cleaned and disinfected periodically.

The traditional so-called humid-mechanical method of disinfection depends on spraying the walls, ceiling and air-channels of the refrigerator room with a disinfectant mostly with a solution of chloramine B. The floor is washed with a solution of a disinfectant at +70 C. As in this case the disinfectant is used in the state of a solution freezing at 0 C., the air in the refrigerated room must be heated to 5l0 C. The heating of such a room in which for several months the temperature was -20 C. or even lower, lasts at least for 5 to 8 days and is rather expensive, as much electric power is used. The

other inconvenience of this method is the necessity of drying the internal space of such a room. When the disinfection is finished, the refrigerated room has to be cooled again. This action requires more time and more electric power. The whole disinfection process lasts, therefore, for about days, during which time the refrigerated room cannot be used for its essential purpose.

Aside from this, as the interceiling isolation has been abandoned, the heating process of one cold storage room (as what must be done before disinfection), causes a greater penetration of warmth and moisture into the rooms on other tiers and significant disturbances in the cooling process are observed.

Ozon was proposed to be used as a disinfectant but as it is effective only when used at a temperature higher than 0 C. and its disinfectant activity is rather weak and it may be applied only in case of air disinfection, there is no reason, therefore, to consider it as a suitable method of disinfection.

The method according to the invention in question is free of all above-mentioned defects and allows quickly and effectively to disinfect a refrigerator room which may be effected at a temperature between 0 C. and C. All inconveniences connected with heating refrigerated rooms are in this way avoided.

The method according to the said invention depends on mechanical disinfection combined with an aerosol, thus far, effected only in medicine for disinfection of air. The chemicals are sprayed in strong concentrations in a form of rnicrosols. As the mist is more condensed in air of low temperature, the disinfection of the room and of the air may be performed simultaneously. The chemicals applied under such conditions are used in the state of solutions which do not freeze at a temperature of --20 C., e.g., in solutions containing 32 percent of glycerol with ethyl alcohol and up to 68 percent of water. Especially effective in this case are the following well known disinfectants: chloramine B and dimethyl lauryl benzyl ammonium bromide. 66 ml. of 1-2 percent solution of these compounds dissolved in the above mentioned mixture of glycerol, alcohol, and water are used for 1 cu. m. of room volume. The quantity of solution which is to be applied depends on time which elapsed from the former disinfection. This kind of solution is sprayed in an unheated refrigerator room by means of a mechanical aerosol for generator of various types (defensor, pulsator, atomizer, pulverizer or with any other suitable equipment).

Tests performed under industrial conditions showed that the method of disinfection applied according to the invention enables to destroy all pathogenic bacteria and to diminish by more than percent the number of microorganisms being in the air and on the disinfected surfaces.

The method according to the invention may be applied in the refrigeration industry as well as in all branches of the alimentary industry in which are used rooms at a low air temperature. This method may be applied in vessel holds destined for the transport of food.

What we claim is:

1. A method of disinfecting refrigerated rooms comprising spraying a mist of a disinfectant substance into a refrigerated room which is at a temperature of between 0 C. and 20 C., said disinfectant substance having a freezing point below 20 C. and consisting essentially of chloramine B or dimethyl lauryl benzyl ammonium bromide dissolved in a solution containing an alcohol anti-freeze substance and water.

2. A method as claimed in claim 1 wherein the antifreeze substance is present in an amount of at least 32% of the solution.

3. A method as claimed in claim 1 wherein said dis- References Cited UNITED STATES PATENTS Yates 2157 Colby et a1 2153 X Davis 212 X Badertscher 424173 Molnar 424-173 Elgin 260-637 Schulze et a1. 424-173 Camp et a1. 424173 Waldron.

MORRIS O. WOLK, Primary Examiner D. G. CONLIN, Assistant Examiner US. Cl. X.R. 

